To solve the problem of excessive random vibration response of a micro-scale mechanical-sensitive component of an optical instrument for a space station, micro-scale and fine modeling of the component was conducted, its mechanical properties were studied, and effective measures were adopted to suppress its random response. First, the boundary coordination of the micro-scale model and the variation problem of the micro-scale finite element were discussed. On this basis and according to the characteristics of the micro-scale structure, four models were established. A system-level random vibration simulation was performed, and the characteristics of the four micro-scale models were studied. Following analysis and comparison of the random response, including the acceleration, displacement, and stress, the micro-scale modeling method was discussed in-depth. Then, random vibration response suppression and a simulation were separately conducted. Finally, mechanical and thermal tests and a testing experiment were performed. Results reveal that the optical instrument has normal functions, the root mean square of the acceleration response of the micro-scale structure is reduced by 42.4%, the stress is reduced by more than 20%, and the stress safety margin is far greater than zero. The maximum relative error of acceleration response for the simulation and test is within 10%. The study thus showes that the proposed four-element modeling method for a cross-section of a micro-scale structure is accurate and reliable.